Conventional spring supports are used in plant engineering or in pipeline construction for the resilient support of components in a loading direction. The use of such spring supports is especially required in such applications in which the loading force, which is exerted by a component on the supporting spring support, varies depending on the situation and resilient yielding should be provided to the loading force. This is the case for example in displacements by expansion of components in the loading direction which can occur by heat for example. Such requirements exist especially in pipeline construction when a respectively different expansion behaviour of the pipelines at different temperatures is obtained and thus a displacement by expansion of the pipeline occurs in the loading direction.
Conventional spring supports are used in such a way that components are placed on the spring supports so that the spring supports carry the load of the components. A component exerts a loading force via its weight along the loading direction on the spring support supporting the component. In order to ensure that the spring support can ensure resilient support of the component, the spring support usually comprises a housing in which a pressure spring is pretensioned, wherein the load of the component is deposited on the pretensioned pressure spring. Depending on the spring characteristic curve of the pressure spring, the pressure spring allows a specific path of displacement of the supported component in the loading direction if the loading force, which is exerted by the component on the spring support, varies by a specific amount. Therefore, conventional spring supports are capable of carrying components and to meet the expansion behaviour of the components, as a result of which impermissibly high tensions and destructions in a system with a respective component can be prevented effectively. Generic spring supports are usually formed in such a way that in their application they allow a path of displacement of up to 10 mm, partly up to 20 mm, and partly even up to 30 mm. For example, the path of displacement is obtained in pipeline construction from the spring characteristic curve and the requirement typically provided in pipeline construction that the loading force which is exerted by a pipeline on a spring support must not vary by more than 25% in all situations of the pipeline system. Generic spring supports are usually used for supporting components which exert a considerable loading force on the spring supports. Generic spring supports are typically used in a loading force range of approximately 0.2 to 400 kN, especially 0.5 to 100 kN.
Conventional spring supports are formed in such a way that they comprise a housing, a pressure plate, a load pipe and a pressure spring. The housing comprises a stand side and an upper side. An opening is provided in the upper side. The pressure plate is arranged in the housing and is displaceable within the housing in the loading direction, wherein the pressure spring is arranged between the pressure plate and the stand side and exerts a spring force on the pressure plate. Thereby the pressure spring is pretensioned in the loading direction in each position of the pressure plate within the housing so that it always presses the pressure plate in the loading direction towards the upper side against the housing. The load pipe is connected to the pressure plate and arranged in such a way that in each position of the pressure plate it extends from the interior of the housing through the opening to the outside. If a component is placed on the load pipe, it is thus supported in a resilient manner because the pressure spring exerts the spring force on the pressure plate and the load pipe is connected to the pressure plate.
A conventional spring support is prepared in the following way for the application for supporting a specific component which exerts a specific loading force: the load pipe is subjected at first to the specific, expected loading force of the component in the loading direction, as a result of which the pressure plate connected to the load pipe assumes a specific position in the housing along the loading direction towards the stand side. The position of the pressure plate in the housing is then fixed by a blocking apparatus. The component can then be placed on the spring support prepared in this manner, wherein the blocking apparatus can be removed after placing the component with the specific loading force, without the pressure plate and thus also the load pipe, substantially changing the respective position in relation to the housing of the spring support.
The height in the loading direction is thus predetermined by the loading force which acts on the spring support in the loading direction or for which the spring support is set. In the case of a number of known spring supports, a slight variation in the height of the spring support in the loading direction is possible irrespective of the respective loading force, in that the relative position of the load pipe to the pressure plate can be varied in a specific section in the loading direction, which is usually in a range of 10 to 30 mm. This allows a slight adjustment of the height to the desired installation environment.
Spring supports are conventionally formed in such a way that they can be used for a great range of loads. The minimal loading force, for which a spring support is capable for resilient support, is usually less than half the maximum loading force for which a spring support is similarly capable for resilient support. This wide range of application is realised in conventional spring supports in such a way that long coil springs are used as pressure springs in the loading direction, the pretension of which can be set by displacing the pressure plate in the housing to the desired loading force. This leads to a respective height of the housing in the loading direction, which is determined by the length of the pressure spring in the loading direction at the lowest possible pretension of the pressure spring.
This configuration of conventional spring supports has thus proven to be inappropriate for a number of fields of application. For example, it is frequently the case in pipeline construction that there is little space beneath the pipelines for housing the spring supports, so that the considerable extension of the spring support housing in the loading direction is frequently problematic. This is usually counteracted in such a way that spring supports of extremely high spring stiffness are used, which then ensures a low height of the housing in the loading direction on the one hand, which on the other hand provides only a very low path of displacement in the loading direction in the case of a variation of the loading force due to the high spring stiffness. This can lead to undesirable tensions in the supported components and thus in a pipeline system for example. A generic spring support is, e. g., disclosed in document U.S. Pat. No. 3,000,600 A. This spring support comprises a pressure plate as well as a spring arranged in the housing of the spring support, wherein the pressure plate is connected with a load pipe and wherein the spring exerts a force on the pressure plate. A distance element which is provided between the upper side of the housing and the spring plate determines the pretension of the spring. Further, there are known spring units with a telescopic housing. For example, document U.S. Pat. No. 4,457,196 A discloses a spring unit encapsulated in a housing having two parts, the spring unit being designed for use in a punching machine. Document EP 2 664 816 A2 discloses a spring designed for a resilient connection of two elements, wherein the spring comprises a housing consisting of two parts which are movable relative to each other.